Astrophysical black holes are known to have formed in recent cosmological times. However, black holes could have also formed in the early universe. These primordial black holes (PBHs) can account for all or part of dark matter [1]}, [2]}, [3]}, [4]}, [5]}, [6]}, [7]}, [8]}, [9]}, [10]}, [11]}, [12]}, [13]}, [14]}, [15]}, [16]}, [17]}, [18]}, [19]}, [20]}, [21]}, [22]}, [23]}, [24]}, [25]}, [26]}, [27]}, [28]}, [29]}, [30]}, [31]}, [32]}, [33]}, [34]}, [35]}, [36]}, [37]}.
In addition, PBHs can be responsible for a variety of astrophysical phenomena including the gravitational events detected at LIGO [38]}, [39]}, [40]}, [41]}, [42]}, [43]},
the formation of supermassive black holes [44]}, [45]}, [46]} or \(r\) -process nucleosynthesis [47]}.
Some models of PBH formation rely on supersymmeric flat directions [23]}, [24]}, [33]}.
Scalar fields associated with supersymmetry can develop a large value at the end of inflation, and then fragment [51]} into lumps of scalar fields, Q-balls, which can become the building blocks of PBHs through their gravitational interactions [23]}, [53]}, [33]}.
